Massera D, et al. - Through 1,680 women recruited from the population-based Cardiovascular Health Study, experts examined the relationships of osteocalcin (OC, a marker of bone formation) and C-telopeptide of type I collagen (CTX, a marker of bone resorption) with long-term incidence of hip fracture in older women. Two hundred and eighty-eight hip fractures occurred over a median of 12.3 years. An association of increasing CTX levels up to the middle-upper range with a significantly higher risk of hip fracture was recognized. Following full adjustment for potential confounders, further increases were linked to a marginally non-significant lower risk. An inverted U-shaped association with incident fracture following adjustment was shown by CTX, with a significant relationship noted only for the comparison of quartile 3 to quartile 1. Both OC and CTX were inversely related to the bone mineral density of the hip in a subset with available measurements. There was an association between CTX (but not OC) levels with incident hip fracture in post-menopausal women, a relationship that was identified as an inverted U-shape.